Hi Leo,
I am in favour of ISP but as far as willem is concerned its definately very simple [ who says complex ], and versatile programmer. You can program a lots of variety of chips with it not only 8051's but also AVR's PIC's a lot of Parrallel and serial ROM's etc. etc. If you are thinking of building a programmer go ahead with WILLEM it is simply better than anything else but REMEMBER REMEMBER ISP IS THE BEST.

Regards,
Prahlad